fn main() {
    // 字符
    let uppercase_s = 'S';
    let lowercase_f = 'f';
    // Compiler interprets a single item in quotations as the "char" data type
    let smiley_face = '😃';

    // 字符串
    // Compiler interprets a series of items in quotations as a "str" data type and creates a "&str" reference
    let string_1 = "miley ";

    // Specify the data type "str" with the reference syntax "&str"
    let string_2: &str = "ace";

    println!(
        "{} is a {}{}{}{}.",
        smiley_face, uppercase_s, string_1, lowercase_f, string_2
    );
}
